Pioneers and Inventors of the Martinetta and of the Variophons
 
Karl Erich Schumann
Jobst P. Fricke
Wolfgang Voigt
Helmut Reuter
Jürgend Schmitz
Karl Erich Schumann,
Discoverer of the Principles of Timbre
Jobst P. Fricke
Inventor of the 
pulse forming process 
Wolfgang Voigt
Inventor of the 
pulse forming process 

Helmut Reuter
Founder of the 
Realton firm
Jürgen Schmitz,
Developer of the 
Variophon